Summary: Open defecation is exceptionally widespread in India, a county with puzzlingly high rates of child stunting. This paper reports a randomized controlled trial of a village-level sanitation program, implemented in one district by the government of Maharashtra. The program caused a large but plausible average increase in child height (95 percent confidence interval [0.04 to 0.61] standard deviations), which is an important marker of human capital. The results demonstrate sanitation externalities: an effect even on children in households that did not adopt latrines. Unusually, surveyors also collected data in districts where the government planned but ultimately did not conduct an experiment, permitting analysis of the importance of the set eligible for randomization.